Liquid-level indicator



April 1o, 192s.- ,l

- ,t w. KusTl-:Rs

LIQUID LEVEL INDICATOR Filed Feb. 1'7. 1925' w.'`|HI|||||1|1I|||||tl|l|lIIIIIIIIIIHIIIIIIIIIIlillIIIUIIIIIIIIIIIIUPatented Apr. 10, 1928.

WILHELM Ks'rnns, or AACHEN, GERMANY.

mourn-LEVEL INDICATOR.

4Application led February 17, ,1925, Serial No. 9,860, and in GermanyFebruary 29, 1924.

lhi's invention relates to liquid-level distance-indicators moreparticularly designed for use in connection with high-lying tankscontaining liquids, such as for instance steam 5 boilers, and comprisinga gauge arranged at a low point by using connecting pipes extending downto such point.

In adhering to the use of an indicating liquid the specific weight ofwhich is greater than that of the tank liquid, I have made out by testsand calculation that, when using an indicating liquid the specic weightof which is double as high as that of the tank liquid, I obtain in thelow-lying gauge of the distance-indicator an'accurate reproduction ofthe liquid-level displayedin an ordina-ry ndicator, the difference ofheight between the two surfaces of the indicating liquid being the sameas the differencek of height between the surfaces of the liquid in thetank or boiler and in the pipe leg connected to the air` or steam spaceof the tank or boiler. The arrangement of the gauge proper at a'lowpoint securelybvoids dangerous errors in reading 2,5 off the indicator,inasmuch as the stoker has always before his -eyes the liquid-level inits real size and thus needs not determine it by the aid of numbers ofratio.

If it should be difficult to procure, f. i. for

steam boilers a suitable indicating liquid the specific wei ht of whichis`exa`et1y 2, the gauge or .in icating vessel containing the liquid mabe arranged at an incline in order to obtain etween the two surfaces ofthe indi.- cating liquid a distancerorn `pending to the (ii'ti'erence ofheight betwee *the water sul'- face in the boiler and that in the pipeleg connected to the steam space of the boiler. The invention will nowbe described with 40 reference to the accompanying drawing whichillustrates, as an embodiment of the invention, a water-level indicatorfor a steam boiler. v

The water-level indicator consists of a U-shaped pipe 0,72, the leg a ofwhich is conl nected to the boiler below the water surface while its legb is connected to it above the water surface. The two pipe legs areentirely lled with water. Interposed between the water columns of thetwo pipe legs at thex lowest point, at whichI they are connected witheach other, is an indicatin liquid c the Y specific weight ofwhich isdoub e or approximately double as high as that of the water so that theliquid o always retains its position between the two water columns.

A cooling ydevice ci arranged above the leg b causes the condensation ofso much steamI that the leg b is always completely iilled with water.When using an indicating liquid with the specific weight 2, thedifference height between the two columns of the indicating liquid ccorresponds exactly to the difference of height between the surface ofthe water `in the boiler and the point of connection of the pipe leg bwith the boiler.

This fact is easily to be proven in connection with the drawing. Let l1,be the vertical distance between the planesof the free surfaces of thewater respectively in leg b and in the boiler, i, the verticaldistance-between the plane of the horizontal surface of the liquid inthe boiler and that of the indicating liquid in le@ a, and h, thevertical distance between theIevels of the indicating liq-4 uid intherespective legs, all as indicated-in the drawing. It is proposed thatthe specific weight of the boiler liquid 'in the pi e branches a and bis 1. Let the specific weig it of the indicating liquidbe rv, then ln anordinary boiler plant the specific weight of the water in the pipebranches a and b is 0.95. The specific weight of the indicator liquidmust correspondingly be 1.9.

The pipe leg w is provided with an enlargement al lying in the range ofthe variations\of the surface of the idicating liquid. The variationsmay therefore be read from the pipe b with suiicient accuracy.

Any liquid which does not Lenter 'into diffusion with water orotheiliquids, may be used as indicating liquid. y"Satisfactory re-.sults have'been attained .with ethylene-bromide of the specific weight2? Having thus described my invention, what Lclaim as new and desire to.secure by Letters-Patent, is 1a e" ,i

A- liquid levell indicator, for the water in steam boilers, com risinga, pi e having a U- the bend an indicating liquid having a spebend at apoint be ow the boiier 4and one leg cie iveight which is approximatelydouble of the bend bein in open communication that of the Water. 10 withthe vcegteconm giningspace of'said boiler In testimony whereof "I havesigned my 5 and the other leg with the space above said :nameto thisspecification.

water, said legs containing independent co1- umns of water between whichis. @Wr-posed .at WILHELM KSTRS.

